need of some degree of control over it, statistics compiled for 1925 indicate that during this year alone the enormous sum of one hundred and forty-one million dollars was expended by American consumers for these commodities. WATER SUPPLY CONTROL Number of Water Examinations As indicated by the summary of analyses as contained in Table I, herewith, there were examined during the biennial period ended June 30, 1926, a total of 2,950 samples. Of this number 1,148 represent samples collected from public systems, or in connection with public systems, 614 were from sources of public interest, furnishing water to hotels, juvenile and tourist camps, schools, etc., while 1,188 were from sources of private character. The following table serves to indicate the comparative distribution of these samples during the ten year period ended June 30, 1926: As bearing upon the reduced number of public water supply examinations and the corresponding diminished attention to this feature for this period (38.9 percent. of all samples as against 49.7 percent for the period preceding), it may be pointed out that the number of semi-public sources represented is largely increased, being 20.8 percent of all samples, as compared to 12 per cent for 1922-1924; also the proportion of private samples examined (40.2 percent, as compared to 38.3 percent) continues to represent a very substantial part of the laboratory work on water. The increase in semi-public samples is due to juvenile camp work. As has been indicated in previous reports, the demand for examinations of private sources, particularly during the summer months and on the part of summer residents, continues to be extensive, the unfortunate part of it being that this, with the examination of camp sources, serves to disrupt in a substantial measure our program of periodical examination of public supplies. If the individual source examinations are to be continued-and it is believed that this is good policy, the only remedy is in the provision of increased working facilities. It is interesting to note that in the quality classifications of the semi-public and private sources, as indicated in Table I, 61.7 percent of the total were rated as representing an unsatisfactory condition in one or more respects. This proportion is very close to that for 1922-1924 (62.9 percent) and also for that of 1920-1922, which was 64.1 percent. As, then explained, this is not to be accepted as meaning that this number of samples represented water actually unfit for drinking or domestic use or that, as to any very large share of these samples, there was any condition of marked or serious pollution. In many cases it does mean, however, that the supplies involved are not being properly maintained, so as to afford a water as clean and free from such items as organic matter, turbidity, objectionable bacteria, and substantial amounts of metallic impurities as is to be desired and might be the case with improved construction, better piping and the exercise of greater care. The problem of lead pollution is still existent. With very nearly the same number of samples examined as for the period preceding (437 as against 428) the proportion of those showing a "substantial" amount of this metal (.050 + parts) was also nearly the same, being 27.0 percent, as against 25.9 percent for the preceding period. Forty-four percent, however, of the lead-conducted samples had as much as 0.025 parts or more, an amount sufficient to occasion toxic manifestations in many cases and therefore to entitle the use of such waters to be classified as of dubious safety. House owners are gradually coming to a realization that for inside piping, brass is far more satisfactory than iron, as well as more economical in the end. For trench work, galvanized iron, with some use of the cement-lined form, is the common practice, but the short life of the first, combined with the tendency to rust, particularly in connection with air-pressure systems, renders this far from being an ideal conductor. At the present time the use of pipe of light gauger copper is becoming extensive. While the cost. is even less than that of lead, history has shown copper pipe to compare very favorably with this metal as to durability, and it imparts no poisonous character to the water. |